Vehicle steering assembly

Abstract

A vehicle steering assembly for controlling movement of a vehicle having independently rotatable left and right ground-engaging traction elements. The steering assembly comprises a steering handle coupled to the panel support structure and extending generally upwardly from the panel support structure. The steering handle comprises a laterally-extending crossmember and at least one upright extension member. The crossmember and the upright extension member are rigidly connected to one another so that shifting of the crossmember relative to the extension member is substantially prevented. The steering handle is shiftable in forward and rearward directions to thereby cause corresponding forward and rearward rotation of both of the left and right traction elements. The steering handle is rotatable in clockwise and counterclockwise directions to thereby cause a change in the relative speeds and directions of rotation of the left and right traction elements.

What is claimed is: 
     
       1. A vehicle steering assembly for controlling movement of a vehicle having independently rotatable left and right ground-engaging traction elements, the vehicle comprising a control panel within reach of an operator of the vehicle, the control panel comprising a panel support structure for supporting control and/or display mechanisms of the vehicle, said steering assembly comprising:
 a plurality of depressible buttons coupled to the panel support structure and configured to cooperatively control the speed and direction of rotation of said left and right traction elements; and 
 a steering handle coupled to said panel support structure and positioned generally over said depressible buttons, 
 wherein said steering handle comprises a laterally-extending crossmember, an upright extension member, and a base, 
 wherein said base presents a lower surface, 
 wherein said lower surface is configured to depress said buttons in response to manipulation of said steering handle by said operator of said vehicle. 
 
     
     
       2. The vehicle steering assembly of  claim 1 , wherein said lower surface has a curved topography. 
     
     
       3. The vehicle steering assembly of  claim 2 , wherein said steering handle is biased toward a neutral position so that said steering handle automatically returns to said neutral position when not acted upon by the operator of the vehicle, wherein said depressible buttons include a front left button, a front right button, a rear left button, and a rear right button, wherein (i) moving said steering handle forward out of said neutral position, without twisting said steering handle, depresses said front left and front right buttons, (ii) moving said steering handle rearward out of said neutral position, without twisting said steering handle, depresses said rear left and rear right buttons, (iii) twisting said steering handle clockwise from said neutral position depresses said rear right and front left buttons, and (iv) twisting said steering handle counterclockwise from said neutral position depresses said front right and rear left buttons. 
     
     
       4. The vehicle steering assembly of  claim 3 , wherein said depressible buttons are upwardly biased, and wherein said steering handle is biased toward the neutral position by said depressible buttons. 
     
     
       5. The vehicle steering assembly of  claim 4 , wherein said lower surface includes a substantially flat front section, a substantially flat rear section, a pair of right-side downwardly sloping sections, and a pair of left-side downwardly sloping sections. 
     
     
       6. The vehicle steering assembly of  claim 5 , wherein (i) moving said steering handle forward out of said neutral position, without twisting said steering handle, causes said substantially flat front portion to contact and depress said front left and front right buttons, (ii) moving said steering handle rearward out of said neutral position, without twisting said steering handle, causes said substantially flat rear portion to contact and depress said rear left and rear right buttons, (iii) twisting said steering handle clockwise from said neutral position causes one of said right-side downwardly sloping sections to contact and depress said rear right button and one of said left-side downwardly sloping sections to contact and depress said front left button, and (iv) twisting said steering handle counterclockwise from said neutral position causes the other of said right-side downwardly sloping sections to contact and depress said front right button and the other of said left-side downwardly sloping sections to contact and depress said rear left button. 
     
     
       7. The vehicle steering assembly of  claim 1 , wherein said steering assembly comprises a plurality of variable switches, wherein each of said variable switches comprises at least one of said depressible buttons, wherein the speed of rotation of said left and right traction elements is determined by how far down said depressible buttons are depressed. 
     
     
       8. The vehicle steering assembly of  claim 1 , wherein said steering controller comprises a hydraulic pilot control valve. 
     
     
       9. The vehicle steering assembly of  claim 1 , wherein a degree of forward or rearward shifting of said steering handle dictates a respective speed of forward or rearward movement of said vehicle, wherein a degree of twisting of said steering handle dictates a severity of turning of said vehicle. 
     
     
       10. The vehicle steering assembly of  claim 1 , wherein said steering assembly further comprises a handle connection assembly for attaching said steering handle to said panel support structure, where said handle connection assembly comprises a tilt hinge and a twist hinge, wherein said tilt hinge is configured to permit said steering handle to tilt forward and rearward relative to said panel support structure on a tilt axis, wherein said twist hinge is configured to permit said steering handle to twist clockwise and counterclockwise relative to said panel support structure on a twist axis. 
     
     
       11. The vehicle steering assembly of  claim 10 , wherein said crossmember extends substantially perpendicular to said twist axis, wherein said twist axis extends through said crossmember. 
     
     
       12. The vehicle steering assembly of  claim 10 , wherein said steering assembly comprises a twist stop assembly for restricting rotation of said steering handle relative to the panel support structure on the twist axis. 
     
     
       13. The vehicle steering assembly of  claim 1 , wherein said crossmember and said upright extension member are rigidly connected to one another so that shifting of the crossmember relative to the extension member is substantially prevented, wherein said steering handle includes only a single upright extension member. 
     
     
       14. The vehicle steering assembly of  claim 1 , wherein said vehicle is a compact utility loader comprising a loader system, a drive system, and a power source for powering the loader system and the drive system, wherein said left and right traction elements each comprises tracks. 
     
     
       15. A vehicle steering assembly for controlling movement of a vehicle having independently rotatable left and right ground-engaging traction elements, the vehicle comprising a control panel within reach of an operator of the vehicle, the control panel comprising a panel support structure for supporting at least one control or display mechanism of the vehicle, said steering assembly comprising:
 a steering handle coupled to the panel support structure and extending away from the panel support structure, 
 wherein said steering handle comprises a laterally-extending crossmember and at least one upright extension member, 
 wherein said steering handle is shiftable in forward and rearward directions to thereby cause corresponding forward and rearward rotation of both of said left and right traction elements, 
 wherein said steering handle is rotatable in clockwise and counterclockwise directions to thereby cause a change in the relative speeds and directions of rotation of said left and right traction elements, 
 wherein said steering assembly further comprises a plurality of depressible buttons positioned generally below said steering handle, 
 wherein said buttons cooperatively control the speed and direction of rotation of said left and right traction elements, 
 wherein the speed of rotation of said left and right traction elements is determined by how far down said depressible buttons are depressed.